Algebra - Wind problem

I can't figure this problem out.

During a 3000 mile flight, a plane encountered a strong tail wind that increased its speed by 100 mi/hour. This increase of speed shortened the flying time by one hour. Find the speed of the plane relative to the ground.

During a 3000-mile flight, a plane encountered a strong tail wind
that increased its speed by 100 mi/hour.
This increase of speed shortened the flying time by one hour.
Find the speed of the plane relative to the ground.

We will use: .

Let = speed of the plane (ground speed).

Normally, it would fly the 3000 miles at mph.. . It would take: . hours.

With the tailwind, its speed is mph.. . To fly 3000 miles, it took only: . hours.
And this is one hour less than its normal time.